| /* Decimal context module for the decNumber C Library. |
| Copyright (C) 2005-2018 Free Software Foundation, Inc. |
| Contributed by IBM Corporation. Author Mike Cowlishaw. |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify it under |
| the terms of the GNU General Public License as published by the Free |
| Software Foundation; either version 3, or (at your option) any later |
| version. |
| |
| GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| for more details. |
| |
| Under Section 7 of GPL version 3, you are granted additional |
| permissions described in the GCC Runtime Library Exception, version |
| 3.1, as published by the Free Software Foundation. |
| |
| You should have received a copy of the GNU General Public License and |
| a copy of the GCC Runtime Library Exception along with this program; |
| see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* Decimal Context module */ |
| /* ------------------------------------------------------------------ */ |
| /* This module comprises the routines for handling arithmetic */ |
| /* context structures. */ |
| /* ------------------------------------------------------------------ */ |
| |
| #include <string.h> /* for strcmp */ |
| #ifdef DECCHECK |
| #include <stdio.h> /* for printf if DECCHECK */ |
| #endif |
| #include "dconfig.h" /* for GCC definitions */ |
| #include "decContext.h" /* context and base types */ |
| #include "decNumberLocal.h" /* decNumber local types, etc. */ |
| |
| /* compile-time endian tester [assumes sizeof(Int)>1] */ |
| static const Int mfcone=1; /* constant 1 */ |
| static const Flag *mfctop=(const Flag *)&mfcone; /* -> top byte */ |
| #define LITEND *mfctop /* named flag; 1=little-endian */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* round-for-reround digits */ |
| /* ------------------------------------------------------------------ */ |
| const uByte DECSTICKYTAB[10]={1,1,2,3,4,6,6,7,8,9}; /* used if sticky */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* Powers of ten (powers[n]==10**n, 0<=n<=9) */ |
| /* ------------------------------------------------------------------ */ |
| const uInt DECPOWERS[10]={1, 10, 100, 1000, 10000, 100000, 1000000, |
| 10000000, 100000000, 1000000000}; |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextClearStatus -- clear bits in current status */ |
| /* */ |
| /* context is the context structure to be queried */ |
| /* mask indicates the bits to be cleared (the status bit that */ |
| /* corresponds to each 1 bit in the mask is cleared) */ |
| /* returns context */ |
| /* */ |
| /* No error is possible. */ |
| /* ------------------------------------------------------------------ */ |
| decContext *decContextClearStatus(decContext *context, uInt mask) { |
| context->status&=~mask; |
| return context; |
| } /* decContextClearStatus */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextDefault -- initialize a context structure */ |
| /* */ |
| /* context is the structure to be initialized */ |
| /* kind selects the required set of default values, one of: */ |
| /* DEC_INIT_BASE -- select ANSI X3-274 defaults */ |
| /* DEC_INIT_DECIMAL32 -- select IEEE 754 defaults, 32-bit */ |
| /* DEC_INIT_DECIMAL64 -- select IEEE 754 defaults, 64-bit */ |
| /* DEC_INIT_DECIMAL128 -- select IEEE 754 defaults, 128-bit */ |
| /* For any other value a valid context is returned, but with */ |
| /* Invalid_operation set in the status field. */ |
| /* returns a context structure with the appropriate initial values. */ |
| /* ------------------------------------------------------------------ */ |
| decContext * decContextDefault(decContext *context, Int kind) { |
| /* set defaults... */ |
| context->digits=9; /* 9 digits */ |
| context->emax=DEC_MAX_EMAX; /* 9-digit exponents */ |
| context->emin=DEC_MIN_EMIN; /* .. balanced */ |
| context->round=DEC_ROUND_HALF_UP; /* 0.5 rises */ |
| context->traps=DEC_Errors; /* all but informational */ |
| context->status=0; /* cleared */ |
| context->clamp=0; /* no clamping */ |
| #if DECSUBSET |
| context->extended=0; /* cleared */ |
| #endif |
| switch (kind) { |
| case DEC_INIT_BASE: |
| /* [use defaults] */ |
| break; |
| case DEC_INIT_DECIMAL32: |
| context->digits=7; /* digits */ |
| context->emax=96; /* Emax */ |
| context->emin=-95; /* Emin */ |
| context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ |
| context->traps=0; /* no traps set */ |
| context->clamp=1; /* clamp exponents */ |
| #if DECSUBSET |
| context->extended=1; /* set */ |
| #endif |
| break; |
| case DEC_INIT_DECIMAL64: |
| context->digits=16; /* digits */ |
| context->emax=384; /* Emax */ |
| context->emin=-383; /* Emin */ |
| context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ |
| context->traps=0; /* no traps set */ |
| context->clamp=1; /* clamp exponents */ |
| #if DECSUBSET |
| context->extended=1; /* set */ |
| #endif |
| break; |
| case DEC_INIT_DECIMAL128: |
| context->digits=34; /* digits */ |
| context->emax=6144; /* Emax */ |
| context->emin=-6143; /* Emin */ |
| context->round=DEC_ROUND_HALF_EVEN; /* 0.5 to nearest even */ |
| context->traps=0; /* no traps set */ |
| context->clamp=1; /* clamp exponents */ |
| #if DECSUBSET |
| context->extended=1; /* set */ |
| #endif |
| break; |
| |
| default: /* invalid Kind */ |
| /* use defaults, and .. */ |
| decContextSetStatus(context, DEC_Invalid_operation); /* trap */ |
| } |
| |
| return context;} /* decContextDefault */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextGetRounding -- return current rounding mode */ |
| /* */ |
| /* context is the context structure to be queried */ |
| /* returns the rounding mode */ |
| /* */ |
| /* No error is possible. */ |
| /* ------------------------------------------------------------------ */ |
| enum rounding decContextGetRounding(decContext *context) { |
| return context->round; |
| } /* decContextGetRounding */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextGetStatus -- return current status */ |
| /* */ |
| /* context is the context structure to be queried */ |
| /* returns status */ |
| /* */ |
| /* No error is possible. */ |
| /* ------------------------------------------------------------------ */ |
| uInt decContextGetStatus(decContext *context) { |
| return context->status; |
| } /* decContextGetStatus */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextRestoreStatus -- restore bits in current status */ |
| /* */ |
| /* context is the context structure to be updated */ |
| /* newstatus is the source for the bits to be restored */ |
| /* mask indicates the bits to be restored (the status bit that */ |
| /* corresponds to each 1 bit in the mask is set to the value of */ |
| /* the correspnding bit in newstatus) */ |
| /* returns context */ |
| /* */ |
| /* No error is possible. */ |
| /* ------------------------------------------------------------------ */ |
| decContext *decContextRestoreStatus(decContext *context, |
| uInt newstatus, uInt mask) { |
| context->status&=~mask; /* clear the selected bits */ |
| context->status|=(mask&newstatus); /* or in the new bits */ |
| return context; |
| } /* decContextRestoreStatus */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextSaveStatus -- save bits in current status */ |
| /* */ |
| /* context is the context structure to be queried */ |
| /* mask indicates the bits to be saved (the status bits that */ |
| /* correspond to each 1 bit in the mask are saved) */ |
| /* returns the AND of the mask and the current status */ |
| /* */ |
| /* No error is possible. */ |
| /* ------------------------------------------------------------------ */ |
| uInt decContextSaveStatus(decContext *context, uInt mask) { |
| return context->status&mask; |
| } /* decContextSaveStatus */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextSetRounding -- set current rounding mode */ |
| /* */ |
| /* context is the context structure to be updated */ |
| /* newround is the value which will replace the current mode */ |
| /* returns context */ |
| /* */ |
| /* No error is possible. */ |
| /* ------------------------------------------------------------------ */ |
| decContext *decContextSetRounding(decContext *context, |
| enum rounding newround) { |
| context->round=newround; |
| return context; |
| } /* decContextSetRounding */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextSetStatus -- set status and raise trap if appropriate */ |
| /* */ |
| /* context is the context structure to be updated */ |
| /* status is the DEC_ exception code */ |
| /* returns the context structure */ |
| /* */ |
| /* Control may never return from this routine, if there is a signal */ |
| /* handler and it takes a long jump. */ |
| /* ------------------------------------------------------------------ */ |
| decContext * decContextSetStatus(decContext *context, uInt status) { |
| context->status|=status; |
| if (status & context->traps) raise(SIGFPE); |
| return context;} /* decContextSetStatus */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextSetStatusFromString -- set status from a string + trap */ |
| /* */ |
| /* context is the context structure to be updated */ |
| /* string is a string exactly equal to one that might be returned */ |
| /* by decContextStatusToString */ |
| /* */ |
| /* The status bit corresponding to the string is set, and a trap */ |
| /* is raised if appropriate. */ |
| /* */ |
| /* returns the context structure, unless the string is equal to */ |
| /* DEC_Condition_MU or is not recognized. In these cases NULL is */ |
| /* returned. */ |
| /* ------------------------------------------------------------------ */ |
| decContext * decContextSetStatusFromString(decContext *context, |
| const char *string) { |
| if (strcmp(string, DEC_Condition_CS)==0) |
| return decContextSetStatus(context, DEC_Conversion_syntax); |
| if (strcmp(string, DEC_Condition_DZ)==0) |
| return decContextSetStatus(context, DEC_Division_by_zero); |
| if (strcmp(string, DEC_Condition_DI)==0) |
| return decContextSetStatus(context, DEC_Division_impossible); |
| if (strcmp(string, DEC_Condition_DU)==0) |
| return decContextSetStatus(context, DEC_Division_undefined); |
| if (strcmp(string, DEC_Condition_IE)==0) |
| return decContextSetStatus(context, DEC_Inexact); |
| if (strcmp(string, DEC_Condition_IS)==0) |
| return decContextSetStatus(context, DEC_Insufficient_storage); |
| if (strcmp(string, DEC_Condition_IC)==0) |
| return decContextSetStatus(context, DEC_Invalid_context); |
| if (strcmp(string, DEC_Condition_IO)==0) |
| return decContextSetStatus(context, DEC_Invalid_operation); |
| #if DECSUBSET |
| if (strcmp(string, DEC_Condition_LD)==0) |
| return decContextSetStatus(context, DEC_Lost_digits); |
| #endif |
| if (strcmp(string, DEC_Condition_OV)==0) |
| return decContextSetStatus(context, DEC_Overflow); |
| if (strcmp(string, DEC_Condition_PA)==0) |
| return decContextSetStatus(context, DEC_Clamped); |
| if (strcmp(string, DEC_Condition_RO)==0) |
| return decContextSetStatus(context, DEC_Rounded); |
| if (strcmp(string, DEC_Condition_SU)==0) |
| return decContextSetStatus(context, DEC_Subnormal); |
| if (strcmp(string, DEC_Condition_UN)==0) |
| return decContextSetStatus(context, DEC_Underflow); |
| if (strcmp(string, DEC_Condition_ZE)==0) |
| return context; |
| return NULL; /* Multiple status, or unknown */ |
| } /* decContextSetStatusFromString */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextSetStatusFromStringQuiet -- set status from a string */ |
| /* */ |
| /* context is the context structure to be updated */ |
| /* string is a string exactly equal to one that might be returned */ |
| /* by decContextStatusToString */ |
| /* */ |
| /* The status bit corresponding to the string is set; no trap is */ |
| /* raised. */ |
| /* */ |
| /* returns the context structure, unless the string is equal to */ |
| /* DEC_Condition_MU or is not recognized. In these cases NULL is */ |
| /* returned. */ |
| /* ------------------------------------------------------------------ */ |
| decContext * decContextSetStatusFromStringQuiet(decContext *context, |
| const char *string) { |
| if (strcmp(string, DEC_Condition_CS)==0) |
| return decContextSetStatusQuiet(context, DEC_Conversion_syntax); |
| if (strcmp(string, DEC_Condition_DZ)==0) |
| return decContextSetStatusQuiet(context, DEC_Division_by_zero); |
| if (strcmp(string, DEC_Condition_DI)==0) |
| return decContextSetStatusQuiet(context, DEC_Division_impossible); |
| if (strcmp(string, DEC_Condition_DU)==0) |
| return decContextSetStatusQuiet(context, DEC_Division_undefined); |
| if (strcmp(string, DEC_Condition_IE)==0) |
| return decContextSetStatusQuiet(context, DEC_Inexact); |
| if (strcmp(string, DEC_Condition_IS)==0) |
| return decContextSetStatusQuiet(context, DEC_Insufficient_storage); |
| if (strcmp(string, DEC_Condition_IC)==0) |
| return decContextSetStatusQuiet(context, DEC_Invalid_context); |
| if (strcmp(string, DEC_Condition_IO)==0) |
| return decContextSetStatusQuiet(context, DEC_Invalid_operation); |
| #if DECSUBSET |
| if (strcmp(string, DEC_Condition_LD)==0) |
| return decContextSetStatusQuiet(context, DEC_Lost_digits); |
| #endif |
| if (strcmp(string, DEC_Condition_OV)==0) |
| return decContextSetStatusQuiet(context, DEC_Overflow); |
| if (strcmp(string, DEC_Condition_PA)==0) |
| return decContextSetStatusQuiet(context, DEC_Clamped); |
| if (strcmp(string, DEC_Condition_RO)==0) |
| return decContextSetStatusQuiet(context, DEC_Rounded); |
| if (strcmp(string, DEC_Condition_SU)==0) |
| return decContextSetStatusQuiet(context, DEC_Subnormal); |
| if (strcmp(string, DEC_Condition_UN)==0) |
| return decContextSetStatusQuiet(context, DEC_Underflow); |
| if (strcmp(string, DEC_Condition_ZE)==0) |
| return context; |
| return NULL; /* Multiple status, or unknown */ |
| } /* decContextSetStatusFromStringQuiet */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextSetStatusQuiet -- set status without trap */ |
| /* */ |
| /* context is the context structure to be updated */ |
| /* status is the DEC_ exception code */ |
| /* returns the context structure */ |
| /* */ |
| /* No error is possible. */ |
| /* ------------------------------------------------------------------ */ |
| decContext * decContextSetStatusQuiet(decContext *context, uInt status) { |
| context->status|=status; |
| return context;} /* decContextSetStatusQuiet */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextStatusToString -- convert status flags to a string */ |
| /* */ |
| /* context is a context with valid status field */ |
| /* */ |
| /* returns a constant string describing the condition. If multiple */ |
| /* (or no) flags are set, a generic constant message is returned. */ |
| /* ------------------------------------------------------------------ */ |
| const char *decContextStatusToString(const decContext *context) { |
| Int status=context->status; |
| |
| /* test the five IEEE first, as some of the others are ambiguous when */ |
| /* DECEXTFLAG=0 */ |
| if (status==DEC_Invalid_operation ) return DEC_Condition_IO; |
| if (status==DEC_Division_by_zero ) return DEC_Condition_DZ; |
| if (status==DEC_Overflow ) return DEC_Condition_OV; |
| if (status==DEC_Underflow ) return DEC_Condition_UN; |
| if (status==DEC_Inexact ) return DEC_Condition_IE; |
| |
| if (status==DEC_Division_impossible ) return DEC_Condition_DI; |
| if (status==DEC_Division_undefined ) return DEC_Condition_DU; |
| if (status==DEC_Rounded ) return DEC_Condition_RO; |
| if (status==DEC_Clamped ) return DEC_Condition_PA; |
| if (status==DEC_Subnormal ) return DEC_Condition_SU; |
| if (status==DEC_Conversion_syntax ) return DEC_Condition_CS; |
| if (status==DEC_Insufficient_storage ) return DEC_Condition_IS; |
| if (status==DEC_Invalid_context ) return DEC_Condition_IC; |
| #if DECSUBSET |
| if (status==DEC_Lost_digits ) return DEC_Condition_LD; |
| #endif |
| if (status==0 ) return DEC_Condition_ZE; |
| return DEC_Condition_MU; /* Multiple errors */ |
| } /* decContextStatusToString */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextTestEndian -- test whether DECLITEND is set correctly */ |
| /* */ |
| /* quiet is 1 to suppress message; 0 otherwise */ |
| /* returns 0 if DECLITEND is correct */ |
| /* 1 if DECLITEND is incorrect and should be 1 */ |
| /* -1 if DECLITEND is incorrect and should be 0 */ |
| /* */ |
| /* A message is displayed if the return value is not 0 and quiet==0. */ |
| /* */ |
| /* No error is possible. */ |
| /* ------------------------------------------------------------------ */ |
| Int decContextTestEndian(Flag quiet) { |
| Int res=0; /* optimist */ |
| uInt dle=(uInt)DECLITEND; /* unsign */ |
| if (dle>1) dle=1; /* ensure 0 or 1 */ |
| |
| if (LITEND!=DECLITEND) { |
| if (!quiet) { |
| #if DECCHECK |
| const char *adj; |
| if (LITEND) adj="little"; |
| else adj="big"; |
| printf("Warning: DECLITEND is set to %d, but this computer appears to be %s-endian\n", |
| DECLITEND, adj); |
| #endif |
| } |
| res=(Int)LITEND-dle; |
| } |
| return res; |
| } /* decContextTestEndian */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextTestSavedStatus -- test bits in saved status */ |
| /* */ |
| /* oldstatus is the status word to be tested */ |
| /* mask indicates the bits to be tested (the oldstatus bits that */ |
| /* correspond to each 1 bit in the mask are tested) */ |
| /* returns 1 if any of the tested bits are 1, or 0 otherwise */ |
| /* */ |
| /* No error is possible. */ |
| /* ------------------------------------------------------------------ */ |
| uInt decContextTestSavedStatus(uInt oldstatus, uInt mask) { |
| return (oldstatus&mask)!=0; |
| } /* decContextTestSavedStatus */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextTestStatus -- test bits in current status */ |
| /* */ |
| /* context is the context structure to be updated */ |
| /* mask indicates the bits to be tested (the status bits that */ |
| /* correspond to each 1 bit in the mask are tested) */ |
| /* returns 1 if any of the tested bits are 1, or 0 otherwise */ |
| /* */ |
| /* No error is possible. */ |
| /* ------------------------------------------------------------------ */ |
| uInt decContextTestStatus(decContext *context, uInt mask) { |
| return (context->status&mask)!=0; |
| } /* decContextTestStatus */ |
| |
| /* ------------------------------------------------------------------ */ |
| /* decContextZeroStatus -- clear all status bits */ |
| /* */ |
| /* context is the context structure to be updated */ |
| /* returns context */ |
| /* */ |
| /* No error is possible. */ |
| /* ------------------------------------------------------------------ */ |
| decContext *decContextZeroStatus(decContext *context) { |
| context->status=0; |
| return context; |
| } /* decContextZeroStatus */ |
| |
